Self Doubt

Question

 

Let X is an Binary Semaphore with waiting Queue in FIFO order.

P1	P2
repeat forever        V(X);                 Compute ;                    P(X);	repeat forever  P(X); Compute ;  V(X);

P1	P2
repeat forever        V(X);                        Compute ;                    V(X);	repeat forever  P(X);  Compute ;  V(X);

 

In which case Starvation for P2 is possible??
 

Comments

you can't say anything about starvation by seeing the code, it's depend upon runtime.

Why not ???

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I want to know exact implementation of UP operation...it wakes up process means put it in ready queue from blocked queue right??

Following steps are the up opeartion 

1. First, check the Queue is empty or not if it is empty then it set the S.value = 1;

2. otherwise select the process from the Queue and Wakeup() it.

Up (BianarySemaphore)

{

if(S.Queue is empty)

{

  S.L = 1 (set value of binary semaphore as 1)
}

else

{

Select the process from the S.queue and Wakeup();

}

}

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you can't say anything about starvation by seeing the code, it's depend upon runtime.

Why not ???

How can you say?